Magnetic-resonance imaging (MRI) apparatuses have been available in which nuclear spins of a subject that is placed in a static magnetic field are magnetically excited by radio frequency (RF) pulses at Larmor frequency, and an image is reconstructed from a magnetic resonance (MR) signal that is generated with this excitation.
Such a magnetic-resonance imaging apparatus causes, for example, cooling water to flow into a gradient coil in which a metal shim is provided, measures the temperature of the cooling water a has flown out from the gradient coil, and controls the temperature of the cooling water that is to flow back into the gradient coil again, thereby suppressing fluctuation in temperature of the metal shim. In another example, a magnetic-resonance imaging apparatus rises, for example, the temperature of a metal shim that is provided in a gradient coil before a protocol is executed, thereby suppressing fluctuation in temperature of the metal shim. Thus, fluctuation in a center frequency of an RF pulse is suppressed, and deterioration of an image quality of an image is suppressed.